Thanks for your response, InshallaTech
I agree with you, I won't ever be going into combat, this'll be a recreational rifle, bedside gun, and something i'll occasionally use for matches. I don't need a 416, although I'd like to make excuses to spend thousands on a new upper!!
I have been very very happy with my MR556 thus far. I would nitride the barrel but it is not an unfired barrel, so I'm just going to keep it as it is.
Thanks for your response